obj sequence to alembic format
I'm trying to do something similar. This video might help you. https://youtu.be/Kx4IU8lUCDs?list=PLxQxoABIf8KYi8c_gVqUGSfIUyxX-NrKf

Basically, put a displace modifier with 0 influence on the object you want to export to trick blender into exporting it as an alembic cache properly.

Let me know if you found a different way to do this. I'm still experimenting and trying to find a good workflow.